Planet Earth is teeming with interesting creatures of all shapes and sizes, but life on our little blue marble wasn't always so diverse. Science tells us that all the life we see on the planet today is the result of primitive organisms evolving over millions and millions of years into much more complex forms. Now, scientists have declared that they've discovered the single common ancestor of all life on the planet, including humans, and it's not exactly a glamorous origin story.

As it turns out, all of us — that means you, your dog, your cat, the mighty blue whale, lowly ant, and even your uncle Bob — all descended from sea sponges. Yep, we're all different branches of an evolution tree that began with a mushy blob of sponge that sits on the bottom of the sea, eats whatever runs into it, and doesn't do much else. Actually, come to think of it, I'm starting to see the human connection...